KROHNE SU 501 EX EN - Manual (Page 22)

Exchange signal conditioning instrument or return it for
repair
3 Should the failure lamp extinguish, you can connect the
sensor again. Separate the signal conditioning instrument
from the connection cable and connect a resistor of 1
kOhm to the sensor input
4 If the failure lamp continues to light, the connection cable is
probably interrupted
Check the connection cable to the sensor
5 Should the failure lamp extinguish, the sensor will be
defective
Exchange sensor or return it for repair
?
The red failure LED of the signal conditioning instrument
lights
l Current value >22 mA
à
Measure the current value on the signal cable to the
sensor
1 Check all connections and connection cables to the sensor
2 If the red failure lamp continues to light, separate the
sensor from the connection cable and connect a resistor of
1 kOhm instead on the signal conditioning instrument
If the failure lamp extinguishes, the sensor is defective.
Check the connected sensor
3 If the failure lamp continues to light, connect the sensor
again. Separate signal conditioning instrument from the
connection cable and connect a resistor of 1 kOhm to the
sensor input.
4 If the failure lamp extinguishes, this is probably due to a
shortcircuit in the connection cable
Check the connection cable to the sensor
5 If the failure lamp continues to light, the signal conditioning
instrument is defective
Exchange signal conditioning instrument or return it for
repair
22 SU 501 Ex - Signal conditioning instrument
Maintenance and fault rectification
27953
-EN
-050616